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Patient handout

Acute diarrhea (ED triage — undifferentiated adult)

PRODUCTION

1. Your condition

This handout is for acute diarrhea (ed triage — undifferentiated adult). Your care team identified this based on: acute watery diarrhea (3+ loose stools/24 h, <14 days) without blood — most often viral (norovirus / rotavirus); supportive only (shane idsa 2017 pmid 29074568).

Other reasons your team may use this plan: bloody dysentery + fever + tenesmus — invasive bacterial (salmonella / shigella / campylobacter / ehec o157:h7); stool culture + shiga toxin (avoid antibiotics for ehec — hus risk per tarr lancet 2005 pmid 21228399); diarrhea + recent antibiotic (clindamycin, fluoroquinolone, cephalosporin) or hospitalized — c difficile naat + gdh + toxin → idsa 2021 fidaxomicin or vancomycin (kelly acg pmid 32198213); diarrhea + crampy abdominal pain + blood + weight loss + extraintestinal manifestations + known ibd or concerning presentation — crohn / uc flare → route gi.crohns.core.v1 / gi.ulcerative-colitis.core.v1 (truelove-witts severity).

4. When to seek emergency care

Call 911 or go to the nearest emergency room right away if you have:

  • Diarrhea + hypotension + tachycardia + oliguria + AMS + lactate ≥4 — severe volume depletion / septic shock; aggressive IV NS/LR + sepsis bundle + cause workup(life-threatening)
  • C diff + hypotension OR ileus OR megacolon OR severe AKI — fulminant C diff; vancomycin 500 mg PO q6h + metronidazole 500 mg IV q8h + surgery consult (Kelly ACG 2021 PMID 32198213)(life-threatening)
  • Bloody diarrhea + EHEC O157:H7 (Shiga toxin positive) + age <5 or >65 or pregnant — HUS risk; AVOID antibiotics + AVOID loperamide + monitor CBC/platelets/LDH/Cr q12-24h (Tarr Lancet 2005 PMID 21228399)(life-threatening)
  • Transverse colon >6 cm on AXR + systemic toxicity (fever, tachycardia, hypotension, AMS, leukocytosis) — toxic megacolon; STAT surgery + IV vancomycin (C diff) or steroids hold (IBD)(life-threatening)
  • Bloody dysentery + fever + tenesmus + stool culture positive (Salmonella, Shigella, Campylobacter) — invasive bacterial; ciprofloxacin 500 mg PO BID × 3-5 d OR azithromycin 1 g (Campylobacter / FQ-resistance); AVOID antibiotics if EHEC (Shane IDSA 2017 PMID 29074568)
  • Bloody diarrhea + ≥6 stools/day + systemic toxicity (HR >90, fever, anemia, ESR/CRP elevation) + known IBD OR concerning presentation — Truelove-Witts severe UC OR severe Crohn; IV methylprednisolone + GI consult; rescue with infliximab or cyclosporine if non-responsive by day 3
  • Acute LLQ pain + bloody diarrhea + elderly vasculopath + AFib / CAD + CT thumbprinting + transmural changes OR right colon ischemia OR pancolitis OR failure to improve in 24-48 h — gangrenous ischemic colitis; STAT surgery(life-threatening)
  • Diarrhea + tachycardia + fever + AMS + AFib + BWPS ≥45 + suppressed TSH + elevated T4 — thyroid storm; PTU + propranolol + hydrocortisone + iodine (AFTER PTU) → endo.thyroid-storm.core.v1(life-threatening)
  • Diarrhea + recent ICI (ipilimumab, nivolumab, pembrolizumab) + grade 3-4 (≥7 stools above baseline + colitis symptoms) — ICI colitis; hold ICI + IV methylprednisolone 1-2 mg/kg + infliximab if refractory by 72 h
  • Diarrhea + HIV (CD4 <100) OR transplant OR chemo OR biologic — opportunistic (CMV colitis, cryptosporidium, microsporidium, MAC); flex sig + CMV PCR + targeted therapy
  • Diarrhea + NAGMA (HCO3 <15, normal anion gap) + K <2.5 — severe bicarbonate + K loss; aggressive LR + K replacement + bicarbonate if pH <7.1

5. Follow-up

Outpatient GI for IBD chronic management; PCP for IBS-D; endocrinology for hyperthyroid / neuroendocrine; chronic IBD on biologic/immunomodulator; C diff recurrence protocol; HUS hematology + nephrology; traveler diarrhea preventive education; fecal impaction bowel regimen; ICI immune-related AE clinic; deprescribing offending drugs (PPI/NSAID/SSRI in microscopic colitis)

6. Sources

Guideline: 2017 IDSA infectious diarrhea (Shane) + 2021 ACG C diff (Kelly) + 2005 Tarr Lancet EHEC/HUS + ACG IBD severity (Truelove-Witts) + Brandt ACG ischemic colitis + ATA/AACE thyroid storm + ASCO/ESMO ICI colitis + WHO ORS + CDC parasitic diarrhea

  1. pubmed.ncbi.nlm.nih.gov/35839362